PCV Valve

[immortal_suby]

Why do they thread them so tight into an aluminum intake?
I've had to remove the intake completely on both cars to get to the pcv valve. I simply could not get enough torque on it with a crows foot. But - huck's method of removing the throttle body sounds like a neat trick.

[CDG]

The tightnes is usually to do with the fact that you have screwed steel into aluminum. the 2 metals like to bond together, thats why they are so hard to remove.
very common phenominum....did I spell that right?

I went out and bought the crows foot and was like "well this should take about twenty minutes". Hah! After hours of taking off the intake manifold and the million vacuum lines and sweating through using a torch on aluminum the little jerk finally came out. The best part is, the oil dipstick still pops out. AAAAAAAACK!

[oab_au]

Originally posted by Crash
I went out and bought the crows foot and was like "well this should take about twenty minutes". Hah! After hours of taking off the intake manifold and the million vacuum lines and sweating through using a torch on aluminum the little jerk finally came out. The best part is, the oil dipstick still pops out. AAAAAAAACK!

The dipstick poping up is a sign that the crankcase is building pressure, because the breather is blocked back at the air box in front of the throttle bodys. This will also cause oil to leak from every where.

The two cam cover breather pipes connect into small passages in the bottom of it. Pull it off and check out these passages for blockage.

Harvey.

[ensteele]

The dipstick also pops out because the O-ring goes south and needs to be replaced. Vibration will work it up over time. That is of course if the pressure that was mentioned before is not the reason.

[oab_au]

Originally posted by ensteele
The dipstick also pops out because the O-ring goes south and needs to be replaced. Vibration will work it up over time. That is of course if the pressure that was mentioned before is not the reason.

I know I am pickey Earl, but why would vibration move it up, gravity should cause the vibration to keep it down. A new O ring may resist the pressure to push it up, for a while........ BUT.

Harvey.

[ensteele]

We are on the opposite (top) of the earth. If it vibrates down there, then it should vibrate up here.

Gosh - here we are talking about vibrators!

Originally posted by oab_au


The dipstick poping up is a sign that the crankcase is building pressure, because the breather is blocked back at the air box in front of the throttle bodys. This will also cause oil to leak from every where.

The two cam cover breather pipes connect into small passages in the bottom of it. Pull it off and check out these passages for blockage.

Harvey.

You wouldn't happen to know of a thread where someone has done this before, would ya? I also have problems with my dipstick I don't think it's popped out since I changed my cam and crank seals

But seriously...

[oab_au]

Originally posted by ensteele
We are on the opposite (top) of the earth. If it vibrates down there, then it should vibrate up here.

Gosh - here we are talking about vibrators!

Godam, never thought about it like that mate, could explain a lot of things. Why our gallons are bigger than yours, Why the moon looks bigger on the horizon, Why Chris prefers polishing tips to Kelli. Back to the drawing board.

Harvey.

[oab_au]

Originally posted by deruvian


You wouldn't happen to know of a thread where someone has done this before, would ya? I also have problems with my dipstick I don't think it's popped out since I changed my cam and crank seals

But seriously...

No mate, this is something that I have been suggesting for a while. I have had a bit of experence with blocked breathers on a number of engines, especially ones that have massive oil leaks from every where, that have been cured, when the breather blockage is located and cleared.

A straight 6cyl push rod Holden(like an old Chev 6) had so much oil coming out the crankshaft oil seal, that the under side of the car dripped oil. The tappet cover, had small holes blocked, that sealed the crankcase from the PCV valve, breather section. Once cleared, the oil leaks stopped.

I had a look at the breather system on the SVX, and the likley spot for a blockage, is this area at the bottom of the air box, there the two cam cover hoses connect in. They don't open into the box there, they connect to a small elbow pipe on the RHS that connects to the air pipe.

With the number of members that have cleaned goo from the throttle bodies, it stands to reasion that these small passages would be blocked also. When this happends, the considerable piston blow-by at full throttle, will pressurise the crank case.

Not hard to check and clear, may save a lot of needless work trying to stop oil leaks.

Harvey.

[immortal_suby]

I've cleaned out the breathers on both svxii now when I did the valve cover gaskets. I shot intake cleaner through them and unbolted the top plastic part where the hose connects. the internal part is riveted on if I recall correctly - the metal plate cant be taken off with a normal threaded fastener - Im fuzzy on this but I do remember being hesitant to try to take that metal plate off for some reason. You can spray cleaner in there and then wash out with water and blow it dry with an airgun.

So far on both cars I haven't noticed either of them being very contaminated - just the usual tarnish came out of them - no big chunks or anything that would suggest they were blocked up.

On the topic of breathers - what would be the effect/gain/loss of fitting free air breathers to the valve covers and sealing off the intake where they normally go in?

Originally posted by immortal_suby
On the topic of breathers - what would be the effect/gain/loss of fitting free air breathers to the valve covers and sealing off the intake where they normally go in?

The EPA would call you a boo-boo head.

[immortal_suby]

Originally posted by Porter


The EPA would call you a boo-boo head.

right....they already hate me anyway......but other than that do we stand to gain anything or destroy the motor?

[oab_au]

Originally posted by immortal_suby
I've cleaned out the breathers on both svxii now when I did the valve cover gaskets. I shot intake cleaner through them and unbolted the top plastic part where the hose connects. the internal part is riveted on if I recall correctly - the metal plate cant be taken off with a normal threaded fastener - Im fuzzy on this but I do remember being hesitant to try to take that metal plate off for some reason. You can spray cleaner in there and then wash out with water and blow it dry with an airgun.

So far on both cars I haven't noticed either of them being very contaminated - just the usual tarnish came out of them - no big chunks or anything that would suggest they were blocked up.

On the topic of breathers - what would be the effect/gain/loss of fitting free air breathers to the valve covers and sealing off the intake where they normally go in?

If you fit filtered breathers to the cam covers, instead of the hoses running back to the air box. The air that is introduced into the engine, through the filters, will not have been measured by the MAF sensor, and the idle and cruise a/f ratio will be leaner.

Matt when you cleaned the breathers at the camcovers, did you clean the passagers, where the hoses connect to the air box in front of the throttle bodies? Thats where I think it would block.

Harvey.

[CDG]

Interestingly enough, the crankcase atmosphere will have some escaped gases, some oil, and in rare occasions, moisture.
if you leave it hooked up to the vacuum, then you will suck it back into the engine and it will be burnt.
If you vent it to the air, you may start to see some leaking gaskets that were already marginal, there may be other issues on some vehicles aswell, but don't recall any.